1. Field of Invention
The present invention relates to a semiconductor process. More particularly, the present invention relates to a stacked structure and a patterning method using the stacked structure.
2. Description of Related Art
In a semiconductor process, usually the pattern is formed on the photoresist layer in a process of lithography. Then, the photoresist layer serves as the etching mask to perform the dry or wet etching process so as to transfer the pattern in the photoresist layer to the layer to be patterned beneath the photoresist layer. Along with the high integration of semiconductor devices, the manufacturing critical dimension (CD) of the integrated circuit increasingly becomes small. Therefore, the resolution required by lithography becomes high. In order to satisfy the demands for high resolution, the thickness of the photoresist layer is gradually reduced. However, if the thickness of the photoresist layer is too thin, in the subsequent etching process, it is possible that the photoresist layer serving as the etching mask is completely etched before completely transferring the pattern to the layer to be patterned beneath the photoresist layer. Therefore, it is urgent to find a way to completely transfer the pattern to the layer thereunder by the use of the thin photoresist layer.